btrfs: ensure that file descriptor used with subvol ioctls is a dir
diff mbox

Message ID 1474461089-1526-1-git-send-email-jeffm@suse.com
State Accepted
Headers show

Commit Message

Jeff Mahoney Sept. 21, 2016, 12:31 p.m. UTC
From: Jeff Mahoney <jeffm@suse.com>

If the subvol/snapshot create/destroy ioctls are passed a regular file
with execute permissions set, we'll eventually Oops while trying to do
inode->i_op->lookup via lookup_one_len.

This patch ensures that the file descriptor refers to a directory.

Fixes: cb8e70901d (Btrfs: Fix subvolume creation locking rules)
Fixes: 76dda93c6a (Btrfs: add snapshot/subvolume destroy ioctl)
Cc: <stable@vger.kernel.org> #v2.6.29+
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
---
 fs/btrfs/ioctl.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

Comments

David Sterba Sept. 22, 2016, 2:42 p.m. UTC | #1
On Wed, Sep 21, 2016 at 08:31:29AM -0400, jeffm@suse.com wrote:
> From: Jeff Mahoney <jeffm@suse.com>
> 
> If the subvol/snapshot create/destroy ioctls are passed a regular file
> with execute permissions set, we'll eventually Oops while trying to do
> inode->i_op->lookup via lookup_one_len.
> 
> This patch ensures that the file descriptor refers to a directory.
> 
> Fixes: cb8e70901d (Btrfs: Fix subvolume creation locking rules)
> Fixes: 76dda93c6a (Btrfs: add snapshot/subvolume destroy ioctl)
> Cc: <stable@vger.kernel.org> #v2.6.29+
> Signed-off-by: Jeff Mahoney <jeffm@suse.com>

Reviewed-by: David Sterba <dsterba@suse.com>
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Patch
diff mbox

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index b2a2da5..7fd939b 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1634,6 +1634,9 @@  static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
 	int namelen;
 	int ret = 0;
 
+	if (!S_ISDIR(file_inode(file)->i_mode))
+		return -ENOTDIR;
+
 	ret = mnt_want_write_file(file);
 	if (ret)
 		goto out;
@@ -1691,6 +1694,9 @@  static noinline int btrfs_ioctl_snap_create(struct file *file,
 	struct btrfs_ioctl_vol_args *vol_args;
 	int ret;
 
+	if (!S_ISDIR(file_inode(file)->i_mode))
+		return -ENOTDIR;
+
 	vol_args = memdup_user(arg, sizeof(*vol_args));
 	if (IS_ERR(vol_args))
 		return PTR_ERR(vol_args);
@@ -1714,6 +1720,9 @@  static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
 	bool readonly = false;
 	struct btrfs_qgroup_inherit *inherit = NULL;
 
+	if (!S_ISDIR(file_inode(file)->i_mode))
+		return -ENOTDIR;
+
 	vol_args = memdup_user(arg, sizeof(*vol_args));
 	if (IS_ERR(vol_args))
 		return PTR_ERR(vol_args);
@@ -2357,6 +2366,9 @@  static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 	int ret;
 	int err = 0;
 
+	if (!S_ISDIR(dir->i_mode))
+		return -ENOTDIR;
+
 	vol_args = memdup_user(arg, sizeof(*vol_args));
 	if (IS_ERR(vol_args))
 		return PTR_ERR(vol_args);